This invention relates to the improvement of an apparatus for opening a delivery valve in a gas reservoir chamber of a compressed gas operated gun.
This type of conventional apparatus was so constructed that a part of the delivery valve is struck by a striker to which momentum is imparted by the force of a spring, thereby causing the delivery valve to be opened. However, since an extremely strong force is required for imparting momentum to the striker, a shock at the time of collision of the striker with the delivery valve is considerably great and therefore causes vibration of the whole gun, which often resulted in missing the mark.
In order to improve such disadvantage, the same applicant as this application proposed a delivery valve opening apparatus in Japanese Pat. No. 678,511, which comprises a compressed gas chamber; a gas reservoir chamber adjacent thereto; a suction check valve arranged in a through-hole of a partition wall between the gas reservoir chamber and the compressed gas chamber; and a delivery valve means consisting of a delivery tube having a flange and slidable gas-tightly in a through-hole which opens into the gas reservoir chamber at the side opposite to the suction check valve, and a delivery valve body arranged coaxially adjacent to the rear end of the delivery tube and slidable in the through-hole; said delivery valve body being engaged at the rear end by one end of an intermediate lever biased by a spring so that an opening at the rear end of the delivery tube may be normally closed by the delivery valve body, and the other end of the intermediate lever being engaged by a lever of a trigger when compressed gas is supplied into the gas reservoir chamber from the compressed gas chamber. In operation of this apparatus, after supplying compressed gas from the compressed gas chamber into the gas reservoir chamber, pull of the trigger causes the delivery tube and the delivery valve body to be moved backwards together to a delivery opening by the compressed gas within the gas reservoir chamber, and then when the delivery tube is mechanically stopped by its flange, the delivery valve body is brought out of engagement with the delivery tube and further moved backwards, whereby the opening at the end of the delivery tube communicates with the delivery opening so that the compressed gas flows through the delivery opening into a barrel bore to thereby discharge a projectile such as pellet therein.